1. Field of the Invention
The present invention relates to an image processing system, an image processing program, and an image processing method. More specifically, the present invention relates to an image processing system, an image processing program, and an image processing method, which accurately extract a repeating pattern present in an image.
2. Description of the Related Art
A method of applying an image to an object, which is so-called texture mapping, is widely known in the field of computer graphics (hereinafter referred to as CG), and is used on a variety of CG systems.
In order to enhance reality, a pattern is repeatedly applied to an object in some cases. However, if consideration is not given to such repetition, the seam portion between the patterns can be unnatural, and reality can be reduced.
When a repeating pattern in an image is extracted or created, the work can be done manually using an image editing software. However, when the pattern is complicated, a large amount of time is needed.
As an example of a method of extracting a repeating pattern in an image, there has been proposed the technique described in Japanese Patent Application Publication No. 2002-198406 (JP-A-2002-198406), for example.
The technique described in JP-A-2002-198406 describes that, using a mathematical technique, such as Fourier transform or an autocorrelation function, a repetition pitch of the repeating patterns is derived from the image that is obtained by imaging an object via an image pickup element, and the region having the repetition pitch is regarded as a region containing a repeating pattern.
However, although, with regard to the technology described in JP-A-2002-198406, it is described that the repetition pitch is derived using a mathematical technique, there is no description of a specific method of calculating the period, and therefore this technology is lacking in feasibility.
An object of the present invention is to accurately extract a repeating pattern.